Power Supplies for LED Driving

CHAPTER 12 Magnetic Materials for Inductors and Transformers

Standard off-the-shelf transformers and inductors were described in Chapter 11. This chapter will describe magnetic materials and techniques for constructing custom transformers and inductors. The primary design requirement is to minimise losses, but to do this we have to consider copper losses, core losses, magnetic saturation, size and construction. Since this book is about designing LED drivers, only the basics of magnetic materials will be given here. For more detail, the reader should consult specialist books on the subject.

An inductor can be made from a coil of wire, wound on a bobbin, and surrounded by a soft magnetic core material. By soft, the meaning is that magnetisation ...